Induction system for internal combustion engines



` Patented May 1, 194s UNITED STATES PATENT OFFE rNDUo'rroN SYSTEM vFon 'nr'lnmranooMBUs'rIoN ENGINES maryan cream-sis, Jr., Jersey city, N. l. Application April 1, 194s, serial No. 482,132 2 '(cl. 12e-122) This invention relates to induction systems for internal combustion engines ofthe type which normally utilize awcarburetor for adrnixing air and fuel lexteriorly ofthe engine and feed the so-called carbureted mixture to the intake manifold of the engine, through which it is distributed A to the several cylinders.

By the present invention the carburetor is entirely eliminatedand the mixture of the fuel with the air, to form a. motive mixture, is effected within the cylinders of the engine.

According to the present invention, air is admitted to the cylinders through the usual manifold or directly into the individual cylinders Without the necessity 4of employing a manifold and the fuel is also introduced directly into the.v cylinders to form the combustible mixture therein.

Ah important feature of the present invention is that the fuel.. is maintained in liquid form until it enters the cylinders of the engine and it is peculiar to this invention that the fuel is fed to the cylinders in highly heated liquid form and under considerable pressure. It is delivered in this condition to the cylinders but, as it is discharged into the cylinders, this discharge is accompanied by such rapid expansion of the fuel that it is immediately vaporizedor gasied. in a '.Eour cycle engine operating according to the present invention, air is drawn into the cylinders for the full suction strokes thereof, but the fuel is admitted to such cylinders preferablynear A the end of the suction stroke and justl before the commencement of the compression stroke. 'i'ms procedure allows the maximum amount of air to enter the cylinders and the fuel injection will not be opposed by pressure which would be present in the cylinders ii the fuel were ad mitted during the compression stroke.

ln order to condition fuel for injection into the engine cylinders as specied, it is first heated to a temperature higher than its boiling point at atmospheric pressure. This heating takes place within a fuel conditioner having a fuel confining loer which will be hereinafterV termed the pressure chamber. This chamber may be electrically heated or otherwise, but may be conveniently` heated by jacketing it and passing through the jacket the waste products of combustion of the engine, so that fuel pumped into the pressure chamber from a suitable source of fuel supply may be heated therein to the desired `temperature with coincident building up of a relatively high vapor pressure head in the pressure chamber.

From the pressure chamber the liquid fuel is fed through an appropriate speed control-valve are vpositively controlled by any .appropriate means synchronized'with the timing of the engine, so as to open in proper timed relation with .the movements of the pistons in said cylinders,

whereby the fuel may be fed in liquid condition under high pressure and temperature to the nozzles and admitted to the respective cylinders near the end of the suction stroke in each o'f them. In this Way tha'fuel is maintained in liquid condition until it passes through the nozzles into the cylinders and these nozzles perform the ft'lncu tion -of expansion valves, so that, as the -fuel passes through the nozles into the cylinders, it is` transformed from liquid into vapor or gaseous state where it readily admixes with the air already in the cylinders, assists .in the heating thereof, and brings about a highly combustible motive mixture. In practice, the duration of opening of the several injector nozzles is adjusted to meet the requirements of the engine by in? waste products of combustion from the engine' through the jacket of said chamber; The apparatus for carrying-out this operation will be presently described, but it may lle-herenoted that the passage of such hot waste products of combustion through said jacket is preferably conf trolled, according to this invention, by. a heat a suitable source through a pump and loetweenv `the pumpand said chamber is a'pressure controller Vwhich is automatically operable, after the manner of a safety valve, to preclude the building up of excessive pressures in the pressure chamber by leading excess pressure back to the fuel supply line or storage tank.

The primary elements which enter into the system of this invention individually embodyllarious liquid in the pressure chamber.

f novel features which will presently be described system of this invention, it is desirable that this chamber carry a suillcient amount of fuel, under relatively high temperature and pressure in order vto fulfill .the requirements of the engine. At the same ,timeit is equally desirable to maintain a vapor space above the surface of the fuel, so that, as the pressure on the fuel increases, due to heating thereof, the vapor within this space may be compressed, in accordance with well known steam-dome principles to exert an elastic pressure upon the surface of the fuel and thus materially facilitate the feeding of such fuel at high pressure andtemperature to the injector nozzles.

In order to insure the presence of this vapor cushion at all times, the present invention provides a iloat control for the feed of liquid fuel into the pressure chamber from the feed pump and the float control means employed for this purpose is such as to compensate automatically for variations in position of the system as a whole. For example, if the system is incorporated in an aircraft, it will not be at all times in any particular position for, while the aircraft is in flight the latter may dive, climb, roll or bank Aand these movements will of course affect the level of the Consequently a float to be controlled by such liquid level must be so arranged as to compensate for the movements of the aircraft and the present invention so provides, as will be apparent from the detailed l description of the drawing whichfollows;

In the drawing I have illustrated the preferred mbodiment ofithe induction system of the present invention but the showing therein made is toA be understood as .for illustrative purposes only and not as defining the limits of the invention.

The drawing illustrates only such detail as is required for a clear understanding of the inven-` -tion and Where conventional parts are shown,

`in section' in the interest of clearness.

l Figure 2 is a section on the plane of the line 2-2 of Figure 1;

Figure 3 is a section on the plane of the line 3--3 of Figures 1 and 2. y

Figure 4 is a vertical section showing more or less -dlagrammatically the construction and operation of one of the lnJector nozzles.

Figure 5 is a fragmental section of a. modified form of flpat valve itting. l

Referring tothe drawing, lis a pipe leading from a fuel supply tank to a pump 2 from which a pipe I leads to the pressure chamber 4 with the surrounding Jacket I5. The pressure chamber and Jacket are preferably spherical in form although they may be cylindrical if desired. At

the point where the pipe 3 connects with the pressure chamber l, it communicates with a duct 6, which extends radially of said chamber and -withinthe confines of the chamber this duct is sembly which, for illustrative purposes. is shown in the drawing as of one-piece casting or fitting therein, while the pin I8 extends in a port and I I, although, in practice, it may be otherwise built or fabricated as desired. In any event it is provided with a tubular radial trunnion 9 provided with a ball-like enlargement 8 rotatably fitted y within the socket 1. A straight through passage III extends through said trunnion radially of the pressure chamber. The fitting II is positioned substantially centrally of the spherical or cylindrical pressure chamber. It is provided therein with a valve chamber I2 having a valve seat I3 for cooperation with a valve It. The stem 'I5 of the valve extends upwardly through a guide I6 and is/secured at its upper end to a float I1. The

valve stem I5 is so associated with the guide IB as to permit the stem to vertically reciprocate In the guide but preclude relative rotation between them. This may be accomplished in any desired Way, as by a key, but, in Figure 3, where a cross section of the valve stem and guide are shown, the stem I5 is illustrated as of non-circular curvilinear cross section while its guide I6 is of a like shape so that the stem cannot rotate within the guide.

The upper end of the valve stem I5 is pivotally secured to the float II, by means of a pin I3, as shown in Figures l and 2, the sealed float being provided with a re-entrant portion I9 into which the upper end of the valve stein may extend for cooperative relation with the pin I8 of the float. 'Ihe axis of the passage through the trunnion 9 is preferably arranged fore and aft of an aircraft when the system of this invention is installed starboard direction, so that by virtue of the pin connection shown, the float is adapted to tilt to compensate for changes in liquid level as the aircraft climbs or dives.

Above the valve chamber I2 and communicating with the seat I3 in the fitting II is a passage 2D which leads downwardly to near the bottom of the pressure chamber (see Fig. l), so that fuel fed from the pump 2 through the pipe 3 to the valve chamber Iz'may, when the valve is opened, pass through the duct 2i! into the lower part of the pressurechamber 4to raise the liquid level therein until it reaches such elevation that the iioat II will lift the valve I4 and shut off the supply of fuel. When the valve I4 is' thus closed, the vpump 2 need not stop. It may continue to operate for I have provided the pressure controller 2I. This controller is connected with the pipe 3 through a branch 22 which communicates with a cylinder 23 and in this cylinder is a piston 2l normally depressed by a spring 25, the tension of which may be controlled by an adjusting screw 26. The adjustment should be such that so long as the pressure in the pressure chamber is below that desired, the spring lwill depress the piston 24 below a feed-back pipe -21 and thus fuel passed through the pump will be delivered to the valve chamber I2. However, when this valve is closed, or when the pressure in the pressure chamber exceeds that predetermined, then back pressure will be exerted through the branch 22 to raise the piston 24 and relieve the pressure through pipe 21 which feeds back to the fuel tank.

The tting II also carries a fuel outlet duct 28 which is open in the upper portion of the pressure chamber and has a trunnion 29 which rotatably nts into a radial socket 3B positioned diametrically opposite the socket 1. The trunnions 29 and 9 are thus in radial axial alinement with one another (and coaxially with the pressure chamber if the latter is cylindrical) and they are all mounted for free rotation within the close the valve.

closely embracing portions of their respective sockets in the pressure chamber. Consequently, `when the pressure chamber is rotated about the common axis of these parts, the oat will maintain the float valve assemblyI in upright position at all times for, as the liquid in the pressure L chamber shifts within said chamber, the float wh shift with it and in so doing will maintain the valve stem le in substantially upright posi--v tion at all times. In this way, v,banking of the aircraft, or its various position in executing a roll, etc., are compensated for. With the tting constituted as described, fuel fed from the pump at substantially atmospheric temperature will be fed by pump 2 into the pressure chamber near the bottom thereof, while fuel from the upper portion of the pressure chamber,

heated condition and under considerable prese, is adapted to be fed through the outlet duct sa. nto and through trunnion 3o and to pipe 3l :and through the speed control'valve 32 to a distrihutingchamber 33. The speed control valve he of any desired type and it may be either manuaily or automatically controlled, whereby may he regulated. The distributor chamber sv be of anydesired shape. It merely serves .-.ccd cavity foi` the connection of a number of .relatively small fuel distributing tubes 34 which lead to the injector nohzles 3'5, one of which is associated with each cylinder, All these distributor tubes are preferably heat insulated placed near to or in the hot exhaust lines to prevent an excessive drop in temperature of the liquid heated fuel passing through said tubes.

The structure of theinjector nozzles may vary within wide limits, but a satisfactory form of construction isshown in Fig. 4. Here a valve housing :it has a threaded shank adapted to be screwed into a cylinder head 31, so that the valve may discharge through a passage 38 into the engine cylinder. The valve has therein a seat 'Siti for cooperation with a sealing member 4B, the stern of which passes upwardly through a packed joint and has associated therewith a spring d2 which normally lifts the stem di to Ylhe upper end of the stem is operated by' a rocker arm 43 pivoted at' llt and acted upon by a push rod or tappet 45, in turn actuated by a cam llt, operable in timed relation to the engine. @ne of the fuel distributing tubes ne amount of fuel fed to the distributing chaxnoperation.

lt will be noted from Figure l that the uppermost portion of the pressure chamber is pro-- te is shown" as connected to the valve casing above the seat il@ and the valve opens inwardly `as illustrated, so as not to be inadvertently unseated during the compression or firing strokes of the piston. The fuel injector may be operated in other walls. than by the rocker arm and tappet arrangement shown, as will be well understood bythose skilled inthe art. Y

The exhaust manifold 4l is connected by a pipe it to a duct $9 which has two branches 5U and til. The branch 50 leads directlyinto the i jacket b of the pressure chamber, while the branch 5i leads to the atmosphere. Interposed in the branch 50 is a slide valve 52, the stem 53 of which is connected to a piston 54 and this piston operates within a cylinder 55 of a heat governor. A spring 56 normally retracts the piston to Awithdraw the valve 52 from the branch 50, but the rear end of thepiston is connected -bya pipe t1 to the fuel outlet pipe 3i of the pressure chamber. A

So long the `the pressure in the pressure cylinder tis below that required, the spring 56 will withdraw the valve 52, )so that the hot exhaust gases from the engine will pass in a straightthrough direction from the pipe 48 through the passage 50 into and through the jacket l of the pressure chamber, to be exhausted, after passing therethrough, to the atmosphere through an outlet 58. However, when the temperature and consequent pressure in the pressure chamber are elevated to the point desired, the pressure within this chamber will be communicated through the pipe 51 to the cylinder 55 to force the piston t4 to the right in Fig. 1 and close the valve 52, so that the hot exhaust gases will exhaust to the atmosphere through the branch 5| until further heating of the liquid in the pressure chamber in practice, the engine may be started by an auxiliary carburetor associated with the intake manifold and operated in the conventional manneruntil the engine heats up and the exhaust gases thereof can raise the temperature of the.

fuel in the pressure chamber, as described. VHowever, if preferred, electrical heating elements may be associated with the pressure chamber to initially furnish the heat desired for its proper vided with a plug 59. the purpose of which is to permit the bleeding of air out of the system when initially charging the pressure chamber `with fuel, for it is desirable that this chamber be filled to a point near its top and that the space above the surfaceb of theliquid be a vapor space rather than an air space.`

In Figure 5 of the drawing I have shown a modified form of float valve mechanism wherein the valve opens in the direction of the flow of liquid from'the pump into the pressure chamber.

Here the valve seat I3 is below the passage Il) and the valve ll seats upwardly against said seat i3. With this type of arrangement, it is of course desirable to pack the valve stem so that fuel from vthe pump will not bypass the valve in entering the pressure chamber by passing through the clearance space between the valve stem,and

itsA guide. Consequently the valve stem in the structure of this figure has its upper, portion lia of the non-circular curvilinear cross section shown in Fig. 3, while substantially the lower half I5b o1' the valve stem is made circular, so

. as to satisfactorily'operate through a packing llili 60. To preclude trapping of liquid above the 1 packing and below the valve stem guide, which trapping would tend to render the operations of the float valvesluggish, the fitting is drilled as indicated at 6I to provide one or more holes which will eliminate such ,trapping of 1iquld`in this space. The structure of Figure 5 'is otherwise as shown in Figure 1 ofthe drawing. In practice the pressure controller 2l may be regulated so asto allow the to be varied at will.

The foregoing detailed description sets pump delivery pressure forth the invention in its preferred practical form, but the invention is to be understood as fully commensurate with the appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. The method of operating an internal combustion engine having a cylinder with a .piston therein 4which comprises: introducing fuel under pressure into a pressure chamber, heating the fuel in said chamber to a temperature higher than its boiling point at atmospheric pressure to place it under corresponding elevated vapor pressure, while the fuel remains in liquid condition, introducing air into the engine cylinder, separately feeding fuel from the pressure chamber to the cylinder, while the fuel remains at a temperature above its boiling point and under the said elevated vapor Apressure with the fuel in liquid condition, relieving the pressure on such liquid fuel upon its entry into the cylinder whereby it enters the cylinder in vaporized'gaseous condition to admix with the air in said cylinder, thereafter compressing the resulting mixture, and thereafter firing the same, and controlling the pressure feed of liquid fuel into the compression chamber by the liquid level of the fuel in said chamber. y

2. The method which comprises: introducing liquid fuel under pressure into a pressure chamber, heating the fuel in said chamber to a temperature higher than its boiling point at atmospheric pressure to place it under a corresponding elevated vapor pressure while the fuel remains in highly heated liquid condition, emitting a quantity of such heated liquid fuel from the pressure chamber and relieving the pressure thereon to cause gasification in the presence of sufficient air to form a combustible mixture, thereafter compressing said combustible mixture and ,thereafter firing the same, and controlling the pressure feed of liquid fuel into the pressure chamber by the liquid level of the fuel in said chamber.

MARYAN GIECIERSKI, JR. 

